Method and apparatus to either heat or cool a pool

ABSTRACT

A method for adjusting the temperature of a swimming pool having a filter system and a waterfall, comprising running the filter system at times of the day such that heat transfer with ambient air is optimized by the action of swimming pool water falling through the ambient air, and further comprising positioning and substantially fixing the position of a movable surface below the water fall to help maximize the heat transfer with the ambient air. For pools without waterfalls, it is further disclosed to utilize a conduit from a submerged water return opening to the movable surface which could be a raft.

BACKGROUND OF THE INVENTION

[0001] Field of the Invention

[0002] The present invention relates to a method and an apparatus whichis helpful in the cost efficient cooling and heating of swimming poolsusing ambient air temperature.

CROSS REFERENCE TO RELATED APPLICATIONS

[0003] Not applicable

BACKGROUND OF THE INVENTION

[0004] For many years there has been the problem of heating swimmingpools during cool weather and cooling down swimming pools in hotclimates during hot weather. The problem of heating swimming poolsduring cool weather can be addressed by any of a number of differentwell know methods such as passing the pool water through a pool heater(i.e., gas, propane or electric heat exchanger). This passing of thepool water through the heat exchanger normally occurs during thefiltration process. The problems with this well known method of heatingpool water are the upfront expense of the pool heater, the spacerequirements for the heater and perhaps most significantly, the veryhigh energy cost of running the pool heater. An additional method ofheating pool water is to use solar heat in the heat exchanger ratherthan fossil fuels or electricity. Examples of patents using solar heatexchangers are set forth in U.S. Pat. No. 4,261,332 entitled “SolarHeating Systems” and U.S. Pat. No. 4,256,087 entitled “Swimming PoolHeater”. These solar heat exchange systems have, inter alia, thedisadvantages of high upfront costs and space requirements.

[0005] There have been fewer prior art inventions relating to cooling aswimming pool which is too warm. Nevertheless, this is a real problem inthe summertime in hot climates. Often pools become so warm (above the90+ degree Fahrenheit) that pool use is not as refreshing as in a coolerpool. U.S. Pat. No. 4,189,791 entitled “Swimming Pool Heating andCooling System” describes a system using air pumps and temperaturecontrollers to control the temperature of the pool using ambient airpumped into pipes located in the pool which act as a heat exchanger.Once again this invention has, inter alia, the problems high up frontcosts and space requirements. U.S. Pat. No. 3,941,154 entitled “SwimmingPool Water Circulation System” describes a water circulation systemwhich contains fountains at the water level which can be pointed intothe air in order to cool the water being recirculated into the pool. Thedisadvantages of such a system are the upfront capital costs and theneed to retrofit old pools.

[0006] What is needed is a simple method to cool or heat a pool. Themethod should be inexpensive to operate and require no retrofitting ofthe pool so that the upfront costs are minimized. All the prior artmethods either are expensive to operate because of energy costs orexpensive to install because of equipment needs or both.

SUMMARY OF THE INVENTION

[0007] Accordingly, it is the object of this invention to provide a lowcost method and apparatus to help in adjusting the temperature ofswimming pools.

[0008] In furtherance of the objects mentioned above, the presentinvention provides a method of cooling or heating a swimming pool usingexisting pool equipment and running the circulation system at times ofthe day which facilitate either heating or cooling of the pool. Forexample, running the circulation system at night to cool a pool duringhot weather or alternatively running the circulation system during thehot part of the day to heat a pool which is too cool.

[0009] This optimized timing of running a pool filter system is simple.To cool the pool, run the filter system during the coolest part of theday (usually late at night). To heat a pool, run the filter systemduring the hottest part of the day (normally during the afternoon andearly evening). Since pool filters must be run some minimum period oftime each day in any event, this optimized timing does not have anyadditional costs. This method works best in pools which have waterfalls(e.g., from the pool spa into the main pool) or in pools which have someother way to have the water fall or run throught the ambient air (e.g.,a fountain). The exposure of the pool water to the ambient air ratherthan being recirculated to the pool under the surface of the watergreatly increases the heat exchange between the ambient air and thepool.

[0010] However, many pools do not have waterfalls, or if they do have awaterfall, the exposure of the pool water to the ambient air is notmaximized because of the relatively limited time period the recirculatedwater is exposed to the ambient air during its fall into the pool.Accordingly, in a preferred embodiment of the invention an apparatus isprovided which is a movable surface which is designed to let therecirculating pool water run over it while being exposed to the ambientair before running or dropping back into the pool. If the pool has onlysubmerged water return openings, then a conduit can be used to channelthe recirculated water onto the top of the movable surface and into theambient air. By changing the size and shape of the movable surface(e.g., a raft) one can maximize the exposure of the recirculating poolwater to the ambient air and accordingly maximize the heat transferbetween the air and water. By having the movable surface irregularlyshaped (e.g., tortuous paths caused by ripples, indentations, pebbleshaped bumps, furrows, etc.) One can maximize the amount of time therecirculating water is on the movable surface and accordingly the heattransfer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a top view of a movable surface situated under a spawaterfall.

[0012]FIG. 2 is a side view of a movable surface and a conduit whichforces recirculated water out of a submerged return opening onto the topof the movable surface.

DETAILED DESCRIPTION OF THE INVENTION

[0013]FIG. 1 shows movable surface 11 situated underneath of waterfall14. (A waterfall for the purpose of this disclosure is any recirculatedwater entering pool surface 13 from above pool surface 13.) In thisembodiment, movable surface 11 has a specific gravity less than that ofwater (i.e., less dense than water) and is accordingly floating on poolsurface 13. In other embodiments of the invention, just a section ofmovable surface 11 could be floating on pool surface 13 (e.g., apontoon-like structure). There are many types of pool waterfalls but inthe FIG. 1, waterfall 14 is caused by the recirculation of pool waterinto spa 20 which is at a higher elevation than pool surface 13 andaccordingly during recirculation, water being recirculated into spa 20falls back into pool surface 13 through waterfall 14 (caused by a lowpoint in spa wall 23).

[0014] In order to maximize the heat transfer of the pool water fallingthrough waterfall 14, movable surface 11 has been positioned andsubstantially fixed in position underneath waterfall 14 (movable surface11 may move on the surface of the water, but should not float away).Therefore, instead of the recirculated pool water entering the poolimmediately after dropping from the spa onto pool surface 13 itcontinues to be exposed to the ambient air because it falls upon movablesurface 11 and is forced to run over its top surface which is exposed toambient air. In a preferred embodiment of the invention, movable surface11 has slightly raised side walls 17 which help channel the water fromthe end of moveable surface 11 situated underneath waterfall 14 to theopposite end of movable surface 11. This channelling of the water alongthe entire length of movable surface 11 to the discharge end 18 ofmovable surface 11 maximizes the time the water is on the movablesurface 11 which also maximizes the heat exchange between the water andthe ambient air.

[0015] This channelling of the recirculated pool water along the entirelength of movable surface 11 could also be accomplished by havingmovable surface 11 slightly slanted downward away from the end ofmovable surface 11 under waterfall 14 and toward discharge end 18.Another method of assuring that water runs over the entire length ofmovable surface 11 could be accomplished by having channels orindentations on the upper surface of movable surface 11. Channels 15near waterfall 14 could be designed to channel the water uniformityacross the top of movable surface 11 by having channels 15 in a fan-likeshape. The remainder of movable surface 11 could be formed to make atortuous path (e.g., squiggly lines or a pebble-like contour) whichmaximizes the amount of time the recirculated pool water stays onmovable surface 11. Alternatively, the upper surface of movable surface11 could be flat or slightly slanted toward discharge end 18. Movablesurface 11 in a preferred embodiment of the invention would double as araft when not in use as a heat transfer surface. In cases where movablesurface 11 has channels 15 or tortuous path 16 on the heat transfer sideof the raft the opposing side could be smooth and usable as a raft byswimmers. This double-sided or dual purpose raft design would assureultimate utility and ease of use. In this way, one would not even haveto take raft out of the pool during use by swimmers since it doubles asa standard raft and can be used as either a normal flotation device forswimmers or as a heat exchanger.

[0016] In order to hold movable surface 11 in place under waterfall 14it is necessary to have some manner of an attachment means of device.There are hundreds or thousands of different types of attachment deviceswell known in the art available to assure that movable surface 11remains under waterfall 14 (e.g., straps, Velcro®, buckles, magnets,hooks, etc.). In addition, numerous movable surfaces 11 could beattached together to maximize surface area for heat transfer. However,in order to use movable surface 11 interchangeably as a raft forswimmers and in order to mimimize retrofitting of the pool wall or pooldeck 21, one preferred embodiment would be to have strap or rope 27detachably connected to movable surface 11 by means of detachableconnection 25 and having the opposite end of rope or strap 27 connectedto weight 22. Detachable connection 25 could be any of a number ofdifferent detachable connections such as Velcro®, snaps, buckles and soforth. In light of the water environment, Velco® may be a preferredattachment device. Using weight 22 positioned on pool deck 21 such thatstrap 27 is taunt against movable surface 11 which allows positioning ofmovable surface 11 essentially anywhere around the perimeter of a poolwithout any retrofitting of pool deck 21 or the pool walls. Also weight22 does not have to be very heavy or bulky since there should not besignificant lateral forces on movable surface 11 to displace it fromunderneath waterfall 14.

[0017] This preferred attachment method and device has the following twoadvantages: (1) The attachment device is easily detachable from movablesurface 11 so that it can be alternatively used as a raft when not inuse as heat transfer surface, and (2) since it relies on weight 22 tohold the movable surface 1 in place, it requires no retrofitting of pooldeck 21 or the walls of the pool.

[0018]FIG. 2 sets forth an embodiment of the invention which ispreferred when a swimming pool does not have a waterfall in which toplace movable surface 11 underneath. Many pools do not have eitherwaterfalls or spas. The water that is recirculated to the pool afterfiltering enters the pool through submerged water return openings belowpool surface 13. In pool configurations where water return opening 33 issubmerged there is a need for a way to get the recirculated water upabove pool surface 13 so that it will be able to run over movablesurface 11. A preferred method to get the recirculated water ontomovable surface 11 is to use conduit 31 (as used herein, conduit 31 canbe any kind of pipe or channel which changes the direction of therecirculated water exiting water return opening 33). One end of conduit31 could abut against pool wall 21 and cover submerged return opening 33at the end of return pipe 32. The recirculated water in return pipe 32normally exits into the pool below pool surface 13 through returnopening 33. However, because of the presence of conduit 31 and thepressure of the water in return pipe 32, the return water insteadtravels up through conduit 31 to exit onto movable surface 11. Once onmovable surface 1 the water is subject to the heat exchange (eithercooling or heating) caused by it's contact with the ambient air.

[0019] In a preferred embodiment, conduit 31 can be attached or detachedvery simply in order to maximize ease of use. This mobility allows thepool to be used safely without a permanent conduit or pipe protrudinginto it. In an experiment, conduit 31 consisted of two separate rigid 2″UL-90° Std. Bend PVC Sch. 40 (issue no. X-33658) conduit from Cantexfitted together with a standard 2″ PVC coupling. When fitted togetherthe two conduits formed “S” shaped pipe approximately 40″ long. One endof this “S” shaped pipe (conduit 31) was abutted against return opening33 and the other end protruded above pool surface 13 and rested againstan end of movable surface 11. The recirculating water pressure in theexperiment was such that it exerted an outward pressure (away from poolwall 21) on conduit 31 which had to be counteracted. Counteracting suchoutward pressure was done by preventing movable surface 11 from movingaway from pool wall 21. In the experiment, this was done by manuallyholding the raft (movable surface 11) in place. Movable surface 11 wasabout 18-20 inches from pool wall 21 and return opening 33 was about16-18 inches below pool surface 13. Accordingly, the position of “S”pipe (conduit 31) was such that the water pressure from return opening33 did not cause the “S” pipe to disengage from either pool wall 21 ormovable surface 11. In short, conduit 11 was stuck in between pool wall21 and movable surface 11 without any need for permanently anchoringconduit 31 to either movable surface 11 or pool wall 21.

[0020] Identical with the attachment means set forth in FIG. 1, movablesurface 11 could also be prevented from moving away from pool wall 21 byusing detachable strap or rope 27 connected to weight 22. (Unlike inFIG. 1, however, movable surface 11 would probably not abut against poolwall 21 because of the need to accomodate conduit 31.) The position ofreturn opening 33 (i.e., depth below pool surface 13) could necessitatedifferent configurations and/or lengths for conduit 31. One especiallypreferred method of addressing varying positions of return opening 33and/or pressure of water exiting return opening 33 is to design conduit31 so that its length may be easily varied. One method of easily varyingthe length of conduit 31 is to make conduit 31 “telescoping pipe” bymeans well known in the art. The varying length of conduit 31 alsorequires varying the length of rope or strap 27 so that the distancefrom movable surface 11 and pool wall 21 can be varied as well.

[0021] The present invention has been described above with reference toa preferred embodiment. However, those skilled in the art will recognizethat changes and modifications may be made in the described embodimentswithout departing from the nature and scope of the present invention.Various changes and modifications to the embodiment herein chosen forpurposes of illustration will readily occur to those skilled in the art.To the extent that such modifications and variatins do not depart fromthe spirit of the invention, they are intended to be included within thescope thereof which is assessed only by a fair interpretation of thefollowing claims, enable those skilled in the art to understand andpractice the same, the invention claimed is:

What 1 claim as my invention is:
 1. A method for adjusting thetemperature of a swimming pool having a filter system and a waterfall,comprising running the filter system at times of the day such that heattransfer with ambient air is optimized by the action of swimming poolwater falling through the ambient air.
 2. The method of claim 1 ,comprising positioning and substantially fixing the position of amovable surface below the waterfall to help maximize the heat transferwith the ambient air.
 3. The method of claim 2 , comprising floating themovable surface on the swimming pool.
 4. The method of claim 3 , whereinthe moveable surface is a raft.
 5. The method of claim 4 , wherein theraft has an irregular surface designed to maximize the time the swimmingpool water remains upon the raft and in contact with the ambient air. 6.The method of claim 5 , wherein the raft is double sided and wherein oneside is designed for use by swimmers and an opposing side is designedfor maximum heat transfer.
 7. A method for adjusting the temperature ofa swimming pool having a surface, a filter system, a perimeter and asubmerged water return opening comprising: (1) installing a conduit witha first end and a second end with the first end running from thesubmergerd water return opening and the second end exiting above thesurface of the pool; and (2) positioning a movable surface underneaththe second end of the conduit.
 8. An apparatus for either heating orcooling a swimming pool having a waterfall and a filter system;comprising a movable surface which can be positioned and substantiallyfixed in position underneath of the waterfall such that it is possibleto optimize heat transfer from ambient air by running the filter systemat times of the day designed to either heat or cool recirculating waterfrom the swimming pool.
 9. The apparatus of claim 8 , wherein themovable surface floats in the swimming pool.
 10. The apparatus of claim9 , wherein the movable surface is a raft.
 11. The apparatus of claim 10, wherein the raft has an irregular surface designed to optimize theheat transfer.
 12. The apparatus of claim 11 , wherein the raft is dualpurpose and can be utilized as either a heat exchanger or a normalflotation device for swimmers.
 13. The apparatus of claim 9 , whereinthe movable surface is attachable to other movable surfaces to maximizethe surface area for the heat transfer.
 14. An apparatus for eitherheating or cooling a swimming pool having a filter system and asubmerged water return opening comprising; (1) a movable surface; and(2) a conduit designed to direct water from the submerged water returnopening to the movable surface such that water runs over the movablesurface and heat transfer occurs as it comes into contact with ambientair.
 15. The apparatus of claim 14 , wherein the movable surface floatsin the swimming pool.
 16. The aparatus of claim 15 , wherein the movablesurface is a raft.
 17. The apparatus of claim 16 , wherein the raft hasan irregular surface designed to optimize the heat transfer.
 18. Theappartus of claim 17 , wherein the raft doubles as both a heat exchangerand a normal flotation device for swimmers.
 19. The apparatus of claim15 , wherein the movable surface is attachable to other movable surfacesto maximize the surface area for the heat transfer.
 20. A method foradjusting the temperature of a swimming pool comprising: runningswimming pool water over a waterfall; and transferring energy betweenthe swimming pool water and the ambient air by impacting the water ontoa movable surface wherein the transfer of energy adjusts the pooltemperature to a desired state.
 21. The method of claim 20 , wherein thedesired state is to lower the temperature of the swimming pool water;the running step further comprising running the water when the ambientair temperature is lower than the swimming pool water temperature. 22.The method of claim 20 , wherein the desired state is to raise thetemperature of the swimming pool water; the running step furthercomprising running the water when the ambient air temperature is higherthan the swimming pool water temperature.